1. Field of the Invention
The present invention relates generally to lasers and, more particularly, to a dual wavelength laser for use in dental therapeutic applications.
2. Description of the Prior Art
There are a number of previously known lasers that are used in dental applications. One such laser is a neodymium doped yttrium aluminum garnet laser (Nd:YAG) which, when excited, produces a pulsed output used for dental therapeutic applications. These dental therapeutic applications include, for example, the cutting and eradication of soft tissue, desensitization of teeth, endontic procedures and other dental procedures.
For an Nd:YAG laser crystal, as well as other laser crystals, the wavelength of the emission is a function of the stimulated emission section and thus the gain of the laser crystal. For an Nd:YAG laser, the highest gain wavelength is 1.06 microns so that, upon excitation, the Nd:YAG laser crystal will normally lase at its highest gain wavelength and thus at 1.06 microns.
The Nd:YAG laser, however, when excited, can also lase at different wavelengths, such as 1.32, 0.96 and 1.44 microns. All of these other wavelengths, however, have a higher lasing threshold, and thus lower gain, than the 1.06 wavelength so that normally the Nd:YAG laser, once excited, lases at its maximum gain wavelength, i.e. 1.06 microns.
For many dental therapeutic applications, the 1.06 micron wavelength of the Nd:YAG laser has proven superior to the other, lower gain wavelengths of the Nd:YAG laser. In other applications, especially the cutting of soft tissue, however, the Nd:YAG laser operated at 1.32 microns has proven superior to the 1.06 microns wavelength due to the higher water absorption at 1.32 microns versus 1.06 microns.
Consequently, it would be desirable to have two lasers in the dental office, i.e. one laser which lases at 1.06 microns and a second laser which lases at 1.32 microns. Such a situation, however, is very costly due to the high cost of each laser.